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ESR-3969 I Most Widely Accepted and Trusted Page 4 of 10
<br /> professional using parameters in Table 2(B) with due Pa = Allowable axial compression capacity (lbf or N) of
<br /> consideration of lateral support provided by the helical piles, which must be limited to the maximum
<br /> surrounding soil and/or structure. allowable values noted in Table 4.
<br /> The elastic shortening of the pile shaft will be Kt=Torque correlation factor per Table 4.
<br /> controlled by the strength and section properties of the T = Final installation torque defined as the last torque
<br /> shaft sections and coupler(s). For loads up to and reading taken when terminating the helical pile
<br /> include the allowable load limits found in this report, the installation; which must not exceed the maximum
<br /> elastic shortening of shaft can be estimated as: installation torque rating noted in Table 4 of this report.
<br /> Ashaft = P L/(A E)
<br /> where: Tension and lateral soil capacities are outside the
<br /> scope of this report and should be determined by a
<br /> Ashaft = Length change of shaft resulting from elastic registered design professional on a project by project
<br /> shortening,in(mm). basis and subjected to approval of the code official.
<br /> P = applied axial load, lbf(N). 4.2 Installation:
<br /> L = effective length of the shaft,in. (mm). 4.2.1 General: The PierTech helical foundation
<br /> A = cross-sectional area of the shaft, see Table systems must be installed by PierTech trained and
<br /> 2(B), in.2(mm2). authorized installers. The PierTech helical foundation
<br /> systems must be installed in accordance with this
<br /> E = Young's modulus of the shaft, see Table 2(B), section (Section 4.2), IBC Section 1810.4.11, the site-
<br /> ksi(MPa). specific approved construction documents (engineering
<br /> For each coupler, an elastic shortening of 0.002 inch plans and specifications), and the manufacturer's written
<br /> installation instructions. In case of conflict, the most
<br /> (0.051 mm) is estimated at allowable shaft load, and a
<br /> slip of 0.260 inch (6.60 mm) is estimated at allowable stringent requirement governs.
<br /> shaft load. For shaft, an elastic shortening of 0.002 inch 4.2.2 Helical Piles: The helical piles must be installed
<br /> per foot of shaft (0.167 mm/rn) is estimated at allowable according to a preapproved plan of placement.
<br /> shaft load. Installation begins by attaching the helical pile lead
<br /> 4.1.4 Helix Capacity (P3): Table 3 describes the section to the torque motor (drive head) using a drive
<br /> tool and drive pin. Next, crowd must be applied to force
<br /> allowable axial compression loads for helical bearing
<br /> the pilot point into the ground at the proper location,
<br /> plates. For helical piles with more than one helix, the
<br /> allowable helix capacity, P3, for the helical foundation inclination and orientation, as described in the placement
<br /> systems and devices, be taken as the sum of the plan. Then the pile must be rotated into the ground in a
<br /> least allowable capacity may each individual helix. smooth,clockwise, continuous manner while maintaining
<br /> sufficient crowd to promote normal advancement
<br /> 4.1.5 Soil Capacity (P4): Table 4 describes the (approximately 3 inches per revolution). Installation
<br /> geotechnical related properties of the piles. The continues by adding extension sections as necessary.
<br /> allowable compressive soil capacity (P4) must be Refer to Sections 3.2.1 and 3.3.6 of this report and the
<br /> determined by a registered design professional in approved construction documents for type, grade, size
<br /> accordance with a site-specific geotechnical report, as and number of bolts and nuts that are required to
<br /> described in Section 4.1.1 combined with the individual connect the shaft sections. Inclination and alignment
<br /> helix bearing method (Method 1) or from field loading shall be checked and adjusted periodically during
<br /> tests conducted under the supervision of a registered installation. Connection bolts between shaft sections
<br /> design professional (Method 2). For either Method 1 or shall be snug-tightened as defined in Section J3 of AISC
<br /> Method 2, the predicted axial load capacities must be 360. Care shall be taken not to exceed the maximum
<br /> confirmed during the site-specific production installation, installation torque rating, as shown in Table 4, of the
<br /> such that the axial load capacities predicted by the helical piles during installation. Helical piles must be
<br /> torque correlation method must be equal to or greater advanced until axial capacity is verified by achieving the
<br /> than what is predicted by Method 1 or 2, described required final installation torque as indicated by the
<br /> above. torque correlation method described in Section 4.1.5,
<br /> The individual bearing method is determined as the and the minimum depth, if any, as specified by the
<br /> sum of the individual areas of the helical bearing plates 9eotechnical report Section 4.1.1.
<br /> times the ultimate bearing capacity of the soil or rock 4.2.3 Type A Side Load Brackets: Type A brackets
<br /> comprising the bearing stratum for helix plates. must be installed as specified in the approved plans.
<br /> The allowable axial must be Installation of brackets requires an area adjacent to the
<br /> determined design the totalcapacity axial load building foundation to be excavated at each location thus
<br /> capacitym predicted dividing either total
<br /> ultimateod 1 or 2, above, exposing the footing, column pad, or grade beam. The
<br /> divided by a safety factor of atleast 2. area to be exposed should be an approximate width of
<br /> 18 inches and should extend below the bottom of the
<br /> With the torque correlation method, the ultimate axial footing or grade beam by approximately 12 inches. Any
<br /> soil capacity (P„it) of the pile and the allowable axial soil soil attached to the bottom of the footing, column pad,
<br /> capacity(Pa)of the pile are predicted as follows: or grade beam should be removed prior to bracket
<br /> P„it= Kt x T (Equation 1) installation.The footing or grade beam must be prepared
<br /> by chipping away the irregularities from the side or
<br /> Pa=0.5 Pit (Equation 2) bottom for a sure bracket attachment. Existing concrete
<br /> where: footing or grade beam capacity must not be altered,
<br /> such as notching of concrete or cutting of reinforcing
<br /> Putt = Ultimate axial compressive capacity (lbf or N) of steel, without the approval of the registered design
<br /> helical pile, which must be limited to the maximum professional and the code official. Prepping of the footing
<br /> ultimate values noted in Table 4. allows for the bracket to be mounted to a reasonably flat,
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